For various logistical and technical reasons, concrete floors are typically made up of a series of individual cast-in-place concrete blocks or slabs referred to herein as “concrete slabs” or “slabs”. These concrete slabs provide several advantages including relief of internal stress due to curing shrinkage and thermal movement. However, there are various known issues with such concrete slabs.
One issue with concrete floors occurs when one of the concrete slabs is damaged and needs to be replaced with a new concrete slab. The damaged concrete slab must be removed, and a new concrete slab must be poured and hardened or cured to properly restore the concrete floor adjacent to the remaining existing concrete slab.
Another issue with concrete floors occurs when part of one of the concrete slabs is damaged and needs to be replaced. In such case, a vertically extending cut is made in the concrete slab to separate the damaged part of the concrete slab from the non-damaged part of the concrete slab. The damaged part of the concrete slab is then removed. A new portion of that concrete slab is poured and hardened or cured to properly restore the concrete slab adjacent to the remaining existing, undamaged part of the concrete slab.
In both of these situations, the new concrete slab is positioned adjacent to one or more other existing concrete slabs or preserved non-damaged portion of an existing concrete slab. For purposes of this disclosure, a preserved non-damaged portion of an existing concrete slab will simply be referred to as an existing concrete slab or a first concrete slab. Furthermore, the newly poured concrete slab will simply be referred to as a new concrete slab or a second concrete slab.
Thus, in both of these situations, a joint will be created between the existing concrete slab and the new concrete slab, Since a joint is created, various known issues involving joints between adjacent concrete slabs (i.e., the interface where one concrete slab meets another concrete slab) need to be considered and addressed.
One known issue with such joints involves the relative vertical movements of the adjacent existing and new concrete slabs relative to each other. The adjacent concrete slabs are preferably configured to move individually, and are also preferably configured with load transferring devices to transfer vertical loads from one concrete slab to the adjacent concrete slab. Transferring vertical loads between adjacent concrete slabs has been accomplished using various different load transferring devices and methods. Various load transferring devices for adjacent concrete slabs are described in U.S. Pat. No. 6,354,760.
U.S. Pat. No. 8,356,955 describes load transferring devices for use between an existing concrete slab and a new concrete slab. U.S. Pat. No. 8,356,955 and FIG. 1 of the present application generally illustrate a known cutting tool 10 cutting a cutaway 70 into a side edge 92 of an existing concrete slab 90. The shape of the cutaway 70 is semi-cylindrical due to the circular saw blade used to cut the cutaway 70.
U.S. Pat. No. 8,356,955 and FIG. 2 of the present application generally illustrate a known somewhat football shaped dowel 20 that has been used or proposed to be used in such known existing concrete slabs. Specifically, one known method generally includes inserting a first portion of the known dowel 20 into the cutaway 70 after the cutaway 70 is formed in the existing concrete slab 90. This known method further includes attaching a known dowel receiving sheath 300 (such as one disclosed in U.S. Pat. No. 6,354,760) over the other portion of the known dowel 20 (i.e., the portion that does not protrude into the cutaway 70). The known method further includes pouring the concrete of the new concrete slab around the dowel receiving sheath 300 that is positioned on the dowel 20 and partially extends into the cutaway 70 of the existing concrete slab 90. When the new concrete cures, the dowel 20 is positioned to transfer loads between the existing concrete slab 90 and the adjacent new concrete slab.
However, one problem that exists with such known dowels 20 and such known dowel receiving sheaths 300 is that the portion of the known dowel 20 that is inserted into the known dowel receiving sheath 300 does not conform to the shape of the known dowel receiving sheath 300. This problem increases relative movement between the new and existing concrete slabs in a direction parallel and perpendicular to the longitudinal axis of the joint, and also reduces loadings per square inch in the new and existing concrete slabs close to the joint when transferring vertical or substantially vertical loads from the existing concrete slab to the adjacent, new concrete slab.
Accordingly, there is a need for improved load transfer devices and methods of using such improved load transfer devices that solve these problems.